The Impact of Control and Complexity on Supply Network Performance: An Empirically Informed Investigation Using NK Simulation Analysis

2017 ◽  
Vol 49 (4) ◽  
pp. 625-659 ◽  
Author(s):  
Ilaria Giannoccaro ◽  
Anand Nair ◽  
Thomas Choi
Author(s):  
Eleonora Bottani ◽  
Gino Ferretti ◽  
Roberto Montanari ◽  
Giuseppe Vignali

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Yunming Wang ◽  
Bo Chen ◽  
Weidong Li ◽  
Duoping Zhang

Influential nodes act as a hub for information transmission in a command and control network. The identification of influential nodes in a network of this nature is a significant and challenging task; however, it is necessary if the invulnerability of the network is to be increased. The existing k-shell method is problematic in that it features a coarse sorting granularity and does not consider the local centrality of nodes. Thus, the degree of accuracy with which the influential nodes can be identified is relatively low. This motivates us to propose a method based on an integral k-shell to identify the influential nodes in a command and control network. This new method takes both the global and local information of nodes into account, introduces the historical k-shell and a 2-order neighboring degree, and refines the k-shell decomposition process in a network. Simulation analysis is carried out from two perspectives: to determine the impact on network performance when influential nodes are removed and to obtain the correlation between the integral k-shell value and its propagation value. The simulation results show that the integral k-shell method, which employs an algorithm of lower complexity, accurately identifies the influence of those nodes with the same k-shell values. Furthermore, the method significantly improves the accuracy with which the influential nodes can be identified.


2013 ◽  
Vol 385-386 ◽  
pp. 1095-1099
Author(s):  
Zhen Hui Cui ◽  
Ting Yang ◽  
Lin Chuan Li ◽  
Zhi Heng Cao

Based on complex network theory and network topology modeling, this paper analyses the characteristics of Power Communication Network. The simulation apply two indicators that is connectivity robustness and network performance function to respectively evaluate the impact of failure for network connectivity and communication efficiency in order to identify vulnerabilities in the network. At last, propose one topology optimization algorithm based on the point referral number to optimize the network structure. The fault simulation analysis shows that the algorithm is effective to enhance the ability of the network against deliberate attacks.


2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.


Author(s):  
Jiawei Huang ◽  
Shiqi Wang ◽  
Shuping Li ◽  
Shaojun Zou ◽  
Jinbin Hu ◽  
...  

AbstractModern data center networks typically adopt multi-rooted tree topologies such leaf-spine and fat-tree to provide high bisection bandwidth. Load balancing is critical to achieve low latency and high throughput. Although the per-packet schemes such as Random Packet Spraying (RPS) can achieve high network utilization and near-optimal tail latency in symmetric topologies, they are prone to cause significant packet reordering and degrade the network performance. Moreover, some coding-based schemes are proposed to alleviate the problem of packet reordering and loss. Unfortunately, these schemes ignore the traffic characteristics of data center network and cannot achieve good network performance. In this paper, we propose a Heterogeneous Traffic-aware Partition Coding named HTPC to eliminate the impact of packet reordering and improve the performance of short and long flows. HTPC smoothly adjusts the number of redundant packets based on the multi-path congestion information and the traffic characteristics so that the tailing probability of short flows and the timeout probability of long flows can be reduced. Through a series of large-scale NS2 simulations, we demonstrate that HTPC reduces average flow completion time by up to 60% compared with the state-of-the-art mechanisms.


2015 ◽  
Vol 727-728 ◽  
pp. 996-999 ◽  
Author(s):  
Su Xia Cui

The issue of WDM network traffic grooming has been a hot in the field of research. The implementation of traffic grooming technology can improve the utilization of wavelength channels, reducing the link delay and the blocking rate of the network, which to improve network resource utilization and optimize network performance. This article mainly studies all-optical network routing algorithm utilizing WDM technology to achieve the dynamic traffic grooming and propose a optimization grooming policy -HaffmanGroom (M) algorithms which based on SONET / WDM ring network. The most important feature of this algorithm is that the SONET / WDM ring network of multiple multicast request packet , with a minimum weight of the light path priority selection method, the flow of requests each group effectively optimize ease . The algorithm takes into account the impact of the link request factor and link hops to optimize the link selection. The simulation results show that under the conditions of factors and the number of hop a request fully consider the impact of these two factors to the link, and can achieve optimal link with the smallest weights for effective data transmission, improving resource utilization, reducing blocking rate in order to achieve the purpose of optimizing network performance.


Author(s):  
R.R. Barton ◽  
L.W. Schruben ◽  
J.C. Ford ◽  
D. Hopkins ◽  
D. Goldsman ◽  
...  

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 693
Author(s):  
Kvitoslava Obelovska ◽  
Olga Panova ◽  
Vincent Karovič

The performance of Wireless Local Area Network (WLAN) is highly dependent on the processes that are implemented in the Medium Access Control (MAC) sublayer regulated by the IEEE 802.11 standard. In turn, various parameters affect the performance of the MAC sublayer, the most important of which is the number of stations in the network and the offered load. With the massive growth of multimedia traffic, research of the network performance depending on traffic types is relevant. In this paper, we present the impact of a high-/low-priority traffic ratio on WLAN performance with different numbers of access categories. The simulation results show different impact of high-/low-priority traffic ratio on the performance of the MAC sublayer of wireless LANs depending on different network-sizes and on network conditions. Performance of the large network with two access categories and with the prevalent high-priority traffic is significantly higher than in the case of using four categories on the MAC sublayer. This allows us to conclude that the performance improvement of the large network with the prevalent high-priority traffic can be achieved by an adaptive adjustment of the access categories number on the MAC sublayer.


2013 ◽  
Vol 805-806 ◽  
pp. 334-337
Author(s):  
Shi Wei Su ◽  
You Wei Zhou ◽  
Wei Xiong

Analysis compares the direct access to a single set of wind power systemTwo groups of wind farm access system directlyMultiple sets of wind farm access system directly And Multiple sets of wind dispersion access system's impact on power system transient stability. And compare the simulation results, Concluded that wind farm access capacity and its topology structure's influence on system transient stability.


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